Piston constructions for opposed-piston engines

A piston, comprising:

• a crown with an end surface;
• the end surface including an elongated bowl adjoined by a curved protruding ridge that cooperates with an end surface of another piston disposed in opposition to form a combustion chamber having a generally ellipsoidal shape;
• the end surface further including a periphery with two aligned notches that extend through the periphery into the bowl;
• a first cooling gallery with an asymmetric profile that rises under the ridge and slants upwardly under a concave portion of the bowl;
• and
• a port positioned in the first cooling gallery to receive a jet of liquid coolant.

A method of cooling opposed pistons of an opposed piston engine, each piston including a skirt, a crown attached to the skirt, the crown having an end surface with a periphery, an elongated bowl adjoined by a curved protruding ridge” and two aligned notches that extend through the periphery into the bowl, wherein the end surface cooperates with the end surface of an opposing piston to define a combustion chamber with a generally ellipsoidal shape, the method comprising, for each piston:

• providing a stream of liquid coolant into an asymmetrical annular gallery that abuts the end surface of the piston such that the stream strikes an interior surface at the highest point of the annular gallery, under the ridge;
• collecting liquid coolant of the stream in the annular gallery;
• and,
• agitating the liquid coolant in the annular gallery in response to reciprocation of the piston.

A piston for an opposed-piston engine, comprising:

• a crown with an end surface;
• the end surface including an elongated bowl adjoined by a curved protruding ridge that cooperates with an identical end surface of another piston when the pistons are disposed in opposition to define a combustion chamber with a generally ellipsoidal shape;
• the end surface further including a periphery with two aligned notches that extend through the periphery into the bowl;
• a skirt fixed to the crown;
• and,
• a biaxial slipper mechanism mounted in the skirt and coupling the piston to a piston rod.